W. Halteman | Geology Reports

USGS2005

Effects of hunting on survival of American woodcock in the Northeast

Numbers of American woodcock ( Scolopax minor ) males counted on the annual singing ground survey (SGS) have declined over the last 35 years at an average rate of 2.3% per year in the Eastern Region and 1.8% per year in the Central Region. Although hunting was not thought to be a cause of these declines, mortality caused by hunters can be controlled. Furthermore, there has been no research on effects of hunting mortality on woodcock populations at local and regional levels on the breeding grounds. We used radiotelemetry to determine survival rates and causes of mortality for 913 woodcock captured during fall 1997–2000 on 7 areas in Maine, New Hampshire, Pennsylvania, and Vermont, USA. Three of 7 sites were closed to hunting. For all sites and all years combined, 176 woodcock died, and 130 were censored, of which 39 were censored mortalities. Predation was the major ( n = 134, 76%) cause of mortality. Mammals accounted for 56% of the predation, raptors accounted for 25%, and 19% was attributed to unknown predators. On hunted sites, 36% of the total mortality ( n = 102) was caused by hunting, 63% by predation, and 1 bird starved. Kaplan-Meier survival curves did not differ between hunted and non-hunted sites among years ( P = 0.46). Overall, point estimates of survival did not differ ( P = 0.217) between hunted (SR = 0.636, SE = 0.04) and nonhunted sites (SR = 0.661, SE = 0.08). We modeled hazard rates from hunting and natural mortality events using program MARK. Akaike's Information Criterion supported using a model with common constant hazards from both hunting and natural causes for groups of sites. Groupings of sites for hazard rates from natural causes were not influenced by whether a site was hunted or not. Models detected no effects of woodcock age and sex ( P = 0.52) on survival. Proportional hazards models comparing hunted and nonhunted sites found no effects of age and sex ( P = 0.45), interactions of age, sex, capture weight, and bill length ( P ≥ 0.269). Our data suggest that current hunting regulations are not causing lower survival of woodcock.

Maine, New Hampshire, Pennsylvania, Vermont↗

USGS2001

Status and habitat relationships of northern flying squirrels on Mount Desert Island, Maine

Northern (Glaucomys sabrinus) and southern (G. volans) flying squirrels occur in Maine, but there is uncertainty about range overlap in southcentral Maine where the southern flying squirrel reaches its geographic range limit. We surveyed flying squirrels on Mount Desert Island (MDI), located along the central Maine coast, to update the current status and distribution of these species. We captured only northern flying squirrels, and populations (> 2 individuals) were located in two conifer stands and one mixed conifer-hardwood stand. All three stands were located in relatively older forests, outside a large area burned in a 1947 fire. Tree diameters were similar between trap stations with and without captures, under-story density was low overall, and there was a trend of higher seedling density at capture locations. Low understory density may allow squirrels more effective gliding movements between trees, which may enhance predator avoidance. Although the southern flying squirrel was reported from MDI numerous times during the 20th century, no voucher specimens exist, and species identification and localities have been poorly documented. Future surveys on MDI should consider collection of voucher specimens to validate subsequent survey efforts and effectively document changes in local biodiversity.

Northeastern Naturalist↗